A technical glitch led the Pentagon to scrub its most recently planned test of a long-range ballistic missile interceptor system. The mid-May cancellation came on the heels of a sharp round of congressional debate on the system's capability and the release of a governmental watchdog report that found the system remains unproven and needs more rigorous testing.
Rick Lehner, a spokesperson for the Pentagon's Missile Defense Agency (MDA), told Arms Control Today May 15 that the agency canceled the experiment of the ground-based midcourse defense (GMD) due to a faulty telemetry unit on the test interceptor's exoatmospheric kill vehicle. Lehner said the unit plays no role in helping the kill vehicle locate and collide with a target in space but relays data back to testers so they can later evaluate the kill vehicle's performance.
The intercept test would have been the first for the system since destroying a mock warhead last September. (See ACT, November 2007 .) Including that success, the system has compiled a record of seven intercepts in a dozen attempts.
Just four of those tests have occurred after December 2002 when President George W. Bush ordered the system's deployment. The MDA has fielded roughly two dozen GMD interceptors in Alaska and California to counter what the administration claims are growing missile threats from Iran and North Korea. The most advanced missiles successfully flight-tested by either country are medium-range missiles.
Lehner said the next system intercept test will take place later this fall as previously scheduled, but before that, the MDA plans to conduct a target flight test to vet some of the system's radars. Lehner noted that the target would be accompanied by decoys, a practice that the MDA suspended at the end of 2002 as it transitioned to an upgraded interceptor and kill vehicle.
An adversary might employ decoys to trick a missile defense into engaging them while letting a warhead escape unscathed. System critics, such as Philip Coyle, a former director of the Pentagon's independent weapons-testing office, claim that the previous decoys used by the MDA were easily distinguishable from the real target, offered no real discrimination challenge to the GMD system, and did not realistically reflect what a foe could employ.
In recent congressional testimony, Lieutenant General Henry Obering, the director of the MDA, defended his agency's past use of decoys and the GMD's ability to deal with decoys and other countermeasures. Appearing April 1 before a subcommittee panel of the Senate Armed Services Committee, Obering stated the current GMD system has "the ability to deal with simple countermeasures, and we've flown against those in our flight-test program." He also said at an April 30 hearing of a subcommittee of the House Committee on Oversight and Government Reform that the system is not yet able to deal with "complex countermeasures" but that it could overcome countermeasures that he anticipated Iran and North Korea might employ.
The April 30 hearing was that subcommittee's third missile defense-related hearing convened this year by Rep. John Tierney (D-Mass.), the panel's chairman. Tierney said he was leading an "extensive and sustained" look at missile defense because of its high costs (the most recent annual budget request for the MDA totaled $9.3 billion), previous failed attempts to develop working anti-missile systems, and concerns about the current system's effectiveness and value.
In his remarks, Tierney cited a March report by the Government Accountability Office (GAO), which conducts studies for lawmakers. That report found the MDA had "enhanced the capability of some assets" and conducted experiments that "provide some assurance" that the overarching Ballistic Missile Defense System (BMDS), of which the GMD system is the long-range centerpiece, will work as designed. But the investigative agency also concluded that "performance of the fielded system is as yet not verifiable because too few tests have been conducted to validate the models and simulations that predict BMDS performance." The GAO also stated that "the tests done to date have been developmental in nature, and do not provide sufficient realism for [the Pentagon's] test and evaluation director to fully determine whether the BMDS is suitable and effective for battle."
Obering conceded that the agency had not done enough flight and intercept testing to validate the models and simulations on which it relies to predict the system's performance, but he also contended that past test results have not invalidated those models or simulations either. "We have not seen any showstoppers," Obering declared.
The sharp questioning of Obering during the hearing by Tierney and other Democrats upset the panel's ranking Republican, Rep. Christopher Shays (Conn.). Decrying the hearing as a "fraud" and "an absolute joke," Shays said that committee members only wanted to "score points" rather than "know how this system works."
Some Democrats contend, however, that the MDA is devoting too much attention to less mature systems at the expense of those that have shown promise. In particular, they have urged the MDA to shift greater spending to the Aegis ship-based system and the mobile land-based Terminal High Altitude Area Defense (THAAD). Both systems have recent successful testing records and are designed to intercept short- to intermediate-range ballistic missiles that Democrats say present a more immediate threat to U.S. troops and allies than the danger posed by long-range missiles to the U.S. homeland. In making their case, the lawmakers have pointed to a 2007 classified Pentagon report that called for nearly doubling the number of Aegis and THAAD system interceptors (133 and 96, respectively) that the MDA planned to procure.
The legislative protests appear to have had some effect. The MDA budget released earlier this year had postponed the acquisition of two THAAD fire units by at least a year (see ACT, March 2008 ), but Obering testified in the recent hearings that the MDA had revised its plans to avoid the delay. Obering and other administration officials also said they intend to alter their long-term plans to acquire additional Aegis and THAAD system interceptors.